What is this? Coma? Comatic aberration?

[frederikboving]

Comes with the Nikon 50mm AF 1.4D + the same in 1.8G.
I tried to stress the lens to produce some coma, and the attached is what I got.
Some long "arms" stretching north and south from the center of the light spot.
This is the extreme corner of the frame you see in the image. Snipe from LR.

[Akira]

This is an illustrative example to explain how coma looks like. 

[frederikboving]

I thought coma would point to the center of the frame?

[Airy]

Indeed. These must be crops from the lower left corner. The two "wings" point away from the center, and are arranged symetrically around the radius.

[Akira]

I thought coma would point to the center of the frame?

If I understand correctly, the direction of the coma will depend on the balance of the correction of the related aberrations.

[Birna Rørslett]

Pure coma, without much chromatic aberrations included.